Accent color rendering broken

Recently I had KDEs accent color rendering stop applying in certain areas…
I have a sea-green accent color selected in system settings which used to colorize various icons, but they have now turned black.

Re-loading the global theme didn’t fix it, nor did selecting a different theme.
Even a newly created user with KDE defaults is rendering the same way.

Here’s a mish-mosh of elements…
image

Dolphin folders appear all black
Dolphin icon in task-manager is all black
Updates-available icon in tray shows a black circle

Any ideas on how to troubleshoot this?